Exposure apparatuses for semiconductor processing are commonly used to transfer images from a reticle onto a semiconductor wafer during semiconductor processing. A typical exposure apparatus includes (i) an illumination system having an illumination source and an illumination optical assembly, (i) a reticle stage assembly that positions a reticle, (iii) a projection optical assembly, and (iv) a wafer stage assembly that positions a semiconductor wafer. With this design, the illumination system illuminates the reticle to transfer images to the wafer.
Lithographers commonly desire to use exposure apparatuses from different manufacturers for the same lithographic process. Unfortunately, exposure apparatuses from different manufacturers exhibit different behavior in optical proximity effects (“OPE”). This can be caused by the unavoidable differences in (i) the illumination sources, (ii) the illumination optical assemblies, (iii) the projection optical assemblies, and/or (iv) the synchronization between the reticle stage assembly and the wafer stage assembly. As a result thereof, exposure apparatuses from different manufacturers, when using the same reticle, will transfer different images to the wafer. Thus, the exposure apparatuses from different manufacturers are not interchangeable.